This invention deals with devices that have the capability to simultaneously manipulate the curling screws of a lip rolling machine while it is in operation and lip rolling machines so modified.
Lip rolling machines are well-known in the prior art and initially were developed during the late 1960's and early 1970's into modern manufacturing equipment. Such devices are used for folding lips or rims of plastic containers operating on a single plastic container delivered from a stack or nest of containers provided to the device. The major component of such devices are the lip rollers and the lip rollers consist of a series of parallel or nearly parallel helical screws having the capability of providing a spiral rim folding maneuver for the containers. Each of the screws has spiral rim folding grooves on the surface for receiving containers having pre-heated lip areas. The rim folding roller is angularly offset relative to the axis of the stack or nest of such containers, such that the portions of the grooves receiving the rims lie in planes perpendicular to the axis of the stack.
One of the earliest devices is disclosed in U.S. Pat. No. 3,337,919, that issued on Aug. 29, 1967 to Brown in which there is described an apparatus for curling the rims or flanges of plastic containers using a plurality of circumferentially spaced forming members, wherein one of the forming members comprises a driven rotatable roll having a rim curling spiral groove adapted to accommodate therein the rims or flanges of the containers (the lip rolling screw), and the other forming members comprising generally smooth surface crowding members maintaining the flange or rim in the groove under such force as to effect conjoint rotation and relative axial movement of the container and the groove-forming member. This prior art device does not have the capacity to manipulate the curling screw while the device is operating.
In another, related patent, U.S. Pat. No. 3,914,102 to Brown, that issued on Oct. 21, 1975 another device is described. It should be noted that the Brown device as described in this patent also does not have the capacity to manipulate the curling screws while the device is running.
In a more recent series of patents, there exists U.S. Pat. No. 6,129,537 that issued on Oct. 10, 2000 to Merz, in which there is described for the first time, a means of adjusting the lip rolling screws. Although this device provides a means for adjusting the lip rollers essentially simultaneously, this can only be accomplished while the device is stopped and not while the equipment is in operation.
In addition, two U.S. patents that issued to Lamson, one, U.S. Pat. No. 6,135,754 that issued on Oct. 24, 2000 and the second, U.S. Pat. No. 6,164,949, that issued on Dec. 26, 2000 disclose devices that allow for the simultaneous manipulation of roller screws while the devices are in operation. Both devices depend on the use of separate systems of slide and common linkages which are described therein as “. . . a plurality of curling screws arranged about a circular space about a center axis, each curling screw rotated to carry out said forming, each curling screw formed with a helical groove engaging said container rim and progressively forming a lip as said container is axially advanced between said curling screws by rotation thereof; a mount for each curling screw for enabling selective adjusting movement causing a selective increase or decrease of the radius of said spacing circle to enable adaptation to different sized containers; said mounting including means for constraining simultaneous radical adjustment movement of said curling screws together while maintaining the location of said center axis of said spacing circle and a selectively operable adjuster acting on all of said curling screws simultaneously to cause said simultaneous movement . . . ”, wherein, “. . . said curling screw mounting comprises a series of pivoted mounting plates each carrying a respective curling screw, said series of mounting plates linked together by a linkage system to pivot in unison with each other.”
U.S. Pat. No. 6,135,754 describes a three roller device, and the U.S. Pat. No. 6,164,949 describes a four roller apparatus, the more common device used today in manufacturing.